selective fire, gas operated 7.62×39mm assault rifle, developed in the Soviet Union by Mikhail Kalashnikov. The AK-47 was one of the first true assault rifles. It has been manufactured in many countries and has seen service with regular armed forces as well as irregular, revolutionary and terrorist organizations worldwide. Even after six decades, due to its durability, low production cost and ease of use, the original AK-47 and its numerous variants are the most widely used and popular assault rifles in the world; more AK-type rifles have been produced than all other assault rifles combined. 1947 Lung transplant (Non-human) by Vladimir Demikhov 1947 Light beam microphone The technique of using a light beam to remotely record sound probably originated with Léon Theremin in the Soviet Union at or before 1947, when he developed and used the Buran eavesdropping system. This worked by using a low power infrared beam (not a laser) from a distance to detect the sound vibrations in the glass windows. Lavrentiy Beria, head of the KGB, used this Buran device to spy on the U.S., British, and French embassies in Moscow 1949 Staged combustion cycle Aleksei Isaev proposed the Staged combustion cycle widely used in rocket engines. 1949 Reactive armour 1950s 1950s Head transplant The first head transplant with full cerebral function (by Vladimir Demikhov) 1950s Magnetotellurics The magnetotelluric technique was introduced independently by Japanese scientists in 1948 (Hirayama, Rikitake), Russian geophysicist Andrey Nikolayevich Tikhonov in 1950 and the French geophysicist Louis Cagniard in 1953. 1950 MESM The first universally programmable electronic computer in continental Europe, developed by Sergey Lebedev. 1950 Berkovich tip 1951 Belousov–Zhabotinsky reaction 1951 Explosively pumped flux compression generator 1952 Masers Invention of the first masers by Nikolay Basov and Alexander Prokhorov who later shared the Nobel Prize in Physics for invention and development of laser technologies with Charles Townes. 1952 Seven Sisters (Moscow) 1952 Carbon nanotubes A 2006 editorial written by Marc Monthioux and Vladimir Kuznetsov in the journal Carbon described the interesting and often misstated origin of the carbon nanotube. A large percentage of academic and popular literature attributes the discovery of hollow, nanometer-size tubes composed of graphitic carbon to Sumio Iijima of NEC in 1991. In 1952 L. V. Radushkevich and V. M. Lukyanovich published clear images of 50 nanometer diameter tubes made of carbon in the Soviet Journal of Physical Chemistry. This discovery was largely unnoticed, as the article was